Purpose: To investigate the change in the prevalence of reduced visual acuity (VA) in Taiwanese school children after a policy intervention promoting increased time outdoors.Design: Prospective cohort study based on the Taiwan School Student Visual Acuity Screen (TSVAS) by the Ministry of Education in Taiwan.Participants: All school children from grades 1 through 6 were enrolled in the TSVAS from 2001 through 2015.Methods: The TSVAS requires each school in Taiwan to perform measurements of uncorrected VA (UCVA) on all students in grades 1 through 6 every half year using a Tumbling E chart. Reduced VA was defined as UCVA of 20/25 or less. Data from 1.2 to 1.9 million primary school children each year were collected from 2001 through 2015. A policy program named Tian-Tian 120 encouraged schools to take students outdoors for 120 minutes every day for myopia prevention. It was instituted in September 2010. To investigate the impact of the intervention, a segmented regression analysis of interrupted time series was performed.Main Outcome Measures: Prevalence of reduced VA. Results: From 2001 to 2011, the prevalence of reduced VA of school children from grades 1 through 6 increased from 34.8% (95% confidence interval [CI], 34.7%e34.9%) to 50.0% (95% CI, 49.9%e50.1%). After the implementation of the Tian-Tian 120 outdoor program, the prevalence decreased continuously from 49.4% (95% CI, 49.3%e49.5%) in 2012 to 46.1% (95% CI, 46.0%e46.2%) in 2015, reversing the previous long-term trend. For the segmented regression analysis controlling for gender and grade, a significant constant upward trend before the intervention in the mean annual change of prevalence was found (þ1.58%; standard error [SE], 0.08; P < 0.001). After the intervention, the trend changed significantly, with a constant decrease by e2.34% annually (SE, 0.23; P < 0.001).Conclusions: Policy intervention to promote increased time outdoors in schools was followed by a reversal of the long-term trend toward increased low VA in school children in Taiwan. Because randomized trials have demonstrated outdoor exposure slowing myopia onset, interventions to promote increased time outdoors may be useful in other areas affected by an epidemic of myopia. Ophthalmology 2020;-:1e8 ª 2020 by the American Academy of Ophthalmology. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).

There is evidence that cardiorespiratory fitness and physical activity significantly reduce cardiovascular risks in adults. A better understanding of the association between cardiorespiratory fitness, physical activity, and childhood obesity is vital in assessing the benefits of interventions to prevent obesity. This study was to examine the relationship between physical activity, body mass index, and cardiorespiratory fitness levels in Taiwanese children. A cross-sectional study was designed. Study participants consisted of 2419 school children (1230 males and 1189 females) aged 12 years old living in a southern Taiwan county with one the highest countrywide rates of childhood obesity. The weight status of the participants was defined as underweight, normal, overweight, or obese according to specific criteria. Cardiorespiratory fitness was then assessed by an 800-m run. Participants were queried on their physical activity habits via a questionnaire survey. The overall prevalence of overweight/obesity was 29.6%. Normal, underweight and overweight boys and girls had an increased odds ratio of being categorized with higher cardiorespiratory fitness than obese one for both gender. A significantly higher level of cardiorespiratory fitness was found in children who engaged in regular physical activity than in children who engaged only in irregular physical activity. Obese children are more likely to lack cardiorespiratory fitness. Physically active children have significantly better cardiorespiratory fitness levels than inactive children. This study supports the conclusion that BMI and physical activity are significantly correlated with cardiorespiratory fitness levels. Findings may provide educational professionals with information to assist their developing effective health promotion programs to healthy weight and improving cardiorespiratory fitness for children.

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